1. Technical Field
This disclosure relates to evaluating communication systems, and more particularly, to systems that evaluate hands free communication systems.
2. Related Art
Some evaluation methods do not consider subjective quality. These evaluations may rate hands free systems as deficient, even though the systems may achieve subjectively good perceived quality.
Conversely, hands free systems that obtain high ratings on certain objective measures may not provide a high perceptible quality. Because objective measures may not necessarily correspond to subjective quality, it may be best for listeners to evaluate systems subjectively by listening to actual speech signals.
Some double talk measures use artificial speech signals to model real speech. The artificial speech may simulate conversations that include double talk. Hands free system features, such as switching characteristics, may be evaluated by measuring switching times or variations in attenuation levels. Slow switching times or large variations in attenuation level may lead to “temporally clipped” output. The initial or final consonants of these sound segments may not be transmitted. Some evaluations that measure switching times and attenuation ranges, may not measure the subjective perceptual quality of these systems.